METHOD:
Have the stock already cold. In a food processor blend in batches : the advocados, peeled and with the stone taken out, the cucumbers chopped and peeled, but saving a small amount to garnish with cream; the tomatoes, peeled, chopped and deseeded. Blend all this together with the stock and a little mint after each batch of vegetables has been blended. Add a little salt and put it in the fridge for at least two hours so it cools. When you go to serve it add the cream and the yoghurt and the remaining mint. Mix everything well and when served in bowls garnish on top with some cucumber from earlier. Serve very cold.